This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A344601 #21 May 26 2021 22:45:30 %S A344601 0,0,2,2,8,6,16,12,30,18,40,36,64,40,82,58,106,72,130,92,174,104,190, %T A344601 140,242,150,268,186,316,220,366,242,426,260,458,322,530,326,568,392, %U A344601 640,434,706,470,798,496,826,566,928,602,996,670,1080,718,1166,792 %N A344601 a(n) = n^2 - A344533(n). %C A344601 All terms are even. %C A344601 This is the number of hidden trees (cf. A344533). %Y A344601 Cf. A344533. %K A344601 nonn %O A344601 1,3 %A A344601 _Paul Curtz_, May 24 2021